Fraser Hale, DVM, FAVD, DipAVDC
D E N T A L
A N D
O R A L
S U R G E R Y
F O R
BOARD-CERTIFIED
VETERINARY DENTAL SPECIALIST
P E T S
This informational page is an attempt to describe a complex subject in limited
space. It should be considered to be very introductory. More in-depth discussions of
this and many other subjects can be found on the Old CUSP Articles page at
www.toothvet.ca. You are encouraged to visit and make use of the resources there
and elsewhere on my website.
Tooth Resorption in Cats
Cats are mysterious creatures and as such are
afflicted with some mysterious ailments. One such
disease has had a number of names over the years
and this is a reflection of how little we truly know
about it. The currently accepted name among
veterinary dentists is simply Tooth Resorption.
Consider the primary or baby teeth. In many species,
including humans, dogs and cats, primary (baby)
teeth erupt early in life but last a short while only to
be replaced by the adult (permanent) teeth which are
intended to remain in place for life. In order for the
primary teeth to fall out, specific cells resorb (eat)
the primary tooth roots. This process begins at the
tip of the root(s) and progresses from there toward
the crown. When there is insufficient root structure
to support the crown, the primary tooth becomes
loose and then falls out.
In the early stages, while the resorption is going on
below the gum line, there is no inflammation or pain
associated with it. Once the resorption breaks
through the level of gum tissue attachment, it
becomes contaminated with oral bacteria, becomes
inflamed and painful. With the primary teeth, this
‘teething pain’ is short-lived as the tooth soon falls
out, the adult tooth erupts and the tissues heal.
Adult tooth roots are not supposed to undergo
resorption. There are supposed to remain intact and
unchanged on their outer surface for life. For
reasons we do not understand, the adult teeth in cats
often do undergo resorption but it is rarely the nice,
organized form of resorption seen in primary teeth
that allows the tooth to quickly fall out and the
tissues to quickly heal.
Tooth Resorption in Cats. © F. A Hale, DVM, FAVD, DiplAVDC, 2011
With the adult teeth, the resorption can start
anywhere on the root(s) of the teeth and can take a
couple of forms. The radiographs bottom left show
normal left mandibular premolars and molar in one
cat and a molar in another cat with advanced type-1
tooth resorption (loss of root structure and bone and
clear demarcation between resorptive lesion and
surrounding tissues). The images bottom right show
the normal lower canine teeth in one cat and lower
canine teeth in another cat in an advanced stage of
type-2 resorption (loss of distinction between root
and bone and no associated bone loss).
In all cases of tooth resorption, the only
rational treatment is extraction of the
affected teeth. There is no way to repair the
damage or halt the progression and these
teeth either are now or soon will be sources
of significant inflammation and pain.
While there are several theories being investigated,
we still do not know what causes tooth resorption in
cats. We do know that lesions that have extended
through the level of gingival attachment are very
painful. We also know that cats that have had some
tooth resorption are likely to develop more. We
currently have no recommendations to prevent new
lesions and have no way of predicting which teeth
will be affected next or when. All we can do is
monitor for new lesions and extract teeth as they
become affected.